package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否登录 过滤器
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器 支持通配符比较
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //获取拦截请求的url
        String requestURI = request.getRequestURI();    // /backend/index.html
        log.info("拦截到的请求url是：{}", requestURI);
        //定义不需要处理的url请求路径
        String [] urls = new String[]{
                "/backend/**",
                "/front/**",
                "/employee/login",
                "/employee/logout",
                "/common/upload",
                "/common/download",
                "/user/sendMsg",
                "/user/login"
        };
        //2.判断本次请求是否需要处理
        Boolean check = check(urls, requestURI);
        //3.如果不需要处理 则直接放行
        if (check){
            log.info("本次请求的url：{}不需要处理 直接放行", requestURI);
            filterChain.doFilter(request, response);
            return;
        }
        //4.判断登录状态 如果已经登录就放行 如果没有登录
        if (request.getSession().getAttribute("employee") != null){
            log.info("员工已经登录 员工的id为{}可以放行", request.getSession().getAttribute("employee"));
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request, response);
            return;
        }
        //5.判断登录状态 如果已经登录就放行 如果没有登录
        if (request.getSession().getAttribute("user") != null){
            log.info("用户已经登录 用户的id为{}可以放行", request.getSession().getAttribute("user"));
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request, response);
            return;
        }
        log.info("未登录");
        //5.如果没有登录则返回没有登录的结果 通过输出流方式响应给前端页面 让前端页面处理响应数据 进行页面跳转
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }

    /**
     * 用来比较当前这个url 是否需要放行
     * @param urls
     * @param requestURI
     */
    public Boolean check(String[] urls, String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
